Three main groups of experiments are proposed to investigate factors controlling response strength, especially in choice situations. Proposed experiments in the first group would further assess the generality of the delay-reduction hypothesis which states that the strength of a stimulus as a conditioned reinforcer is a function of the reduction in time to reinforcement correlated with the onset of that stimulus. We have completed an experiment suggesting that this theory of choice and conditioned reinforcement can account for the relative strength of observing responses, i.e., responses whose only consequence is the production of stimuli correlated with the availability of reinforcement. The rate of observing is an index of conditioned reinforcement. Several proposed experiments would analyse the determinants of observing and also test the generality of the delay-reduction hypothesis. The second group of experiments explores issues in self-control with a variety of procedures and with both pigeons and human subjects. These experiments will further assess the delay reduction hypothesis and will attempt to construct a viable theory of self-control that will have useful applications. The third set of experiments continues our investigation of the symmetrical nature of the law of effect, seeking to gain a more thorough appreciation of the extent to which the empirical relations that describe behavior maintained by positive reinforcement also describe behavior maintained by aversive control.